Brewing with the Aurochs: Carbonation Speaks Volumes

This blog post goes out to all the homebrewers and beer enthusiasts. If you like beer, then it is always nice to learn more about the man’s greatest beverage. If you do not like beer, then turn up the volume on your headset, and feel free to tune us out.

Today, we are going to talk about carbonation, more specifically the term “Volumes of CO2” as it applies to beer styles. We have already posted about carbonation and how it impacts flavor, aroma, mouthfeel, head retention, and presentation of a beer in our previous post. You probably remember that carbonation is an important component of beer. It is time to take this a step forward and understand what brewers refer to as volumes of carbon dioxide and how it impacts style.

Quite simply, carbon dioxide (CO2) is soluble in beer. The colder the beer, the more carbon dioxide that will be absorbed into the liquid. The warmer it is, the less carbon dioxide that will be dissolved. The higher the pressure, the more carbon dioxide that will be dissolved. The lower the pressure, the less carbon dioxide that will be dissolved. As you can probably guess, brewers can control the amount of CO2 dissolved in beer by controlling the temperature and pressure of the beer.

The amount of carbon dioxide dissolved into a beer determines the volume of CO2. For example, one volume of CO2 would mean that for every fluid ounce of beer there would be an fluid ounce of CO2 dissolved in a beer. Two volumes of CO2 would mean that for every fluid ounce of beer, there is two fluid ounces of CO2 dissolved in the beer. Three volumes of CO2 would mean that for every fluid ounce of beer, there would be three volumes of CO2 dissolved in the beer. Four volumes of CO2 would mean that…no I’m totally kidding. You get it.

Different beer styles are best suited for certain levels of carbonation. The typical carbonation levels for a few beer styles are listed below.

Dry stout: 1.6 – 2.0 volumes of CO2

American pale ale: 2.2 – 2.8 volumes of CO2

Belgian-style white: 2.2 – 2.6 volumes of CO2.

German weizen: 3.6 – 4.5 volumes of CO2.

If you recall the previous diagram, a German Weizen would require dissolving approximately twice as much carbon dioxide into the beer as a dry stout. The high carbonation of a German Weizen leads to its effervescence and refreshing nature. It would not be the same if it was less carbonated. If you want to see the impact of carbonation on a beer, open it up, pour it, and taste it. Then let it sit out for 30 minutes to an hour and taste it again. It will lose carbonation over time, and its flavor profile should change. Most beers will taste completely different as they warm up and lose carbonation.